1. Field of the Invention
The invention relates to a communication system which transmits a communication signal and a control signal through a common channel.
2. Related Background Art
In a radio telephone system, a timer of a predetermined time is provided in order to prevent an uncomfortable sound which is caused due to communication of control information before communication of speech when a key entry operation is performed in a radio slave terminal a voice circuit is closed for the predetermined time.
However, as shown in FIG. 4, in the case where communication of a control signal with a communication control device in association with a key operation in the radio slave takes longer than the predetermined closure time of the voice circuit because, for example, signal transmission is repeated since radio throughout is bad or there is a delay of processes in the communication control device or there are a number of control information, or the like, there is a problem in that an uncomfortable sound which is caused by the communication of the control information with the communication control device is heard from the radio slave.